Yield Stress-microstructure of Washed TiO2 Suspensions at the Point of Zero Charge

Research output: Contribution to conferenceConference presentation/ephemera

Abstract

The yield stress and microstructure of washed, relatively monodisperse spherical zirconia (ZrO2) and titania (TiO2) suspensions at the isoelectric point (pI) were characterised. The yield stress was found to be dependent upon the particle size. At a given solid concentration, the finer suspensions produced a larger yield stress due to the higher particle concentration and hence, a greater density of attractive interaction. At pI, only the van der Waals force is in play. Vitrified fractal microstructures of these suspensions at pI were captured by cryo-SEM. A power law relationship described the (maximum) yield stress–volume fraction data for both oxides which is consistent with the prediction of scaling theory. An exponent value of ∼3 was obtained for both oxides. The fractal dimension (Df) extracted from this exponent value of the scaling law for large aggregate cluster interaction in the slow flow regime was ∼2.3. The theoretical fractal structure with the same Df constructed from monodisperse spherical particles based on the off-lattice variable-Df model showed strong resemblance to the cryo-SEM imagery of the vitrified structure for both oxides.
Original languageEnglish
Publication statusPublished - 2016
EventThe XVIIth International Congress on Rheology: ICR2016 - Kyoto, Japan
Duration: 8 Aug 201613 Aug 2016

Conference

ConferenceThe XVIIth International Congress on Rheology
CountryJapan
CityKyoto
Period8/08/1613/08/16

Fingerprint Dive into the research topics of 'Yield Stress-microstructure of Washed TiO2 Suspensions at the Point of Zero Charge'. Together they form a unique fingerprint.

  • Cite this

    Au, P. I., Liu, J., & Leong, Y-K. (2016). Yield Stress-microstructure of Washed TiO2 Suspensions at the Point of Zero Charge. Paper presented at The XVIIth International Congress on Rheology, Kyoto, Japan.